George Floyd death: Video appears to show cops spitting on a protester, police department claims they spat on the grass

A disturbing video has emerged online appearing to show US police officers spitting on a detained protester in the state of Virginia.

Witnesses can be heard screaming and shouting at the officers, with one yelling, "We got that on camera!"

The incident happened in the city of Richmond during a protest over the death of George Floyd, an unarmed black man who died last week after a police officer knelt on his neck for nine minutes during an arrest.

In a statement, the Richmond Police Department (RDP) denied any protesters were spat on.

"A frame-by-frame analysis of a viral video that appears to show RPD officers spitting on a detained prisoner shows it did not happen as activists have claimed," the department said on Twitter.

"The video - taken during a demonstration on Monument Ave - shows officers coughing and spitting onto the grass surrounding a monument."

Officers had been exposed to tear gas which is why they were coughing and spitting, the department said. It claims a "slow-motion analysis" of the video showed the officers spat on the grass, not the detained protester.

Protests are continuing across the US over the death of Floyd. President Donald Trump has repeatedly called for "law and order", earlier this week threatening to deploy the US military to restore order, as rioting spread to various states.

"My fellow Americans -my first and highest duty as President is to defend our great country and the American people," he told reporters.

"All Americans were likely sickened and revolted by the brutal death of George Floyd.

"We cannot allow the righteous cries and peaceful protesters to be drowned out by an angry mob."